Reciprocating doctor for papermaking and allied machines



Now/3, 1942. vA. E. BROUGHTON RECIPROCATING DOCTOR PAPER MAKING AND ALLIED MACHINES Filed May 24.` 1959 2 Sheets-Sheet 1 A. E.l `BRouesl-rroN l Nov. 3, 1.942. 2,300,908-

REIPRocATING DocToR FOR PAPER MAKING AND ALLIED MACHINES Filed May 24, 1939 2 Sheets-Sheet 2 Patented Nov. 3. 1942 UNITED, STATESV PATENT OFFICE aEorPaocA'rING Docroa Eon PAPER- MAKING AND ALLIED MAoHmns Arthur E. Broughton, Glens Falls, N. Y.r Application May l24, 1939, serial No. 275,394

- 1 Claim. (Cl. 92-74) 'I'his invention relates to doctors for the rollers and cylinders of paper making. machines and allied machines. v.

To clean and clear the rollers and cylinders of such machines as paper making machines, it isv highly desirablevto `employ reciprocating doctors.

Many of the rollers and cylinders of these machines are of considerable length and in order to properly mount these reciprocating doctors, supports of suilicient `strength andv rigidity must be employedto assure correct and uniform pressure of the doctor blades over the full width of the rolls without permitting the doctor blades to sag, twist or vibrate.

It .is the common practice at present'to employ heavy supporting structures for the doctor blades and to reciprocate these heavy supporting structures with the blades. This necessitates the use of a great deal of power,

It is the main object of the present invention to provide anovel and improved doctor for rolls which includes a heavy supporting structure which extends across the width of the roll and is stationary and a light weight blade carrier and a light weight doctor blade carried thereby, the

blade carrier being mounted and guided in the supporting structure for reciprocation therein by an expenditureof but a small amount of power and the supporting structure acting toproperly.

hold the blade carrier and blade to assure unithe roll.

form pressure of the blade over the full width of p .Another object is to provide a structure such asY above specied together with means permitting movement of the Iblade holder in the supporting structure with a minimum of friction 'while preventing twisting or turning of the blade holder relative to the supporting structure.

The objects and advantages of the invention will more fully appear from the following description, madev in connectipn with the accompanying drawings, in which like reference characters refer to the same or similar out the various views and in whic Fig. 1 is a plan view of a doctor embodying the 4 5 5 of Fig. 2, as indicated by the arrows; I

Fig. 6 is a view in vertical section of one of the ball bearing rollers employed; and

parts throughl Fig. 7 is a plan view of a connecting, yoke employed.

In Fig. 3 there is indicated a portion of a roller A of the type employed on paper making machinesand other analogous machines and over a portion of the surface of which a web of paper is adapted to travel. To clean and clear such a roller, it is desirable to employ a reciprocating doctor, the doctor of the present invention being devised for such purpose and analogous purposes. As used on a paper making machine a roll such as the roller A is as flong as the width of the sheet being formed and is accordingly of considerable length to extend across between the two side frames (not illustrated) of the machine.

In accordance with the present invention there is provided a heavy shaft 8 of such a length as to extend across between the two side frames adjacent the roller A and this shaft may be conven- -iently journaled in bearings 9 attached to' any suitable supporting structure such as supports B. Attached to the shaft 8 is a heavy supporting bar lII) which may take the form Aof an angle bar as illustrated. Secured to one of the flanges of this angle bar as by screws I I is a heavy supporting head I2, this head preferably having a projecting flange I 2a partially received within a rabbet formed in the flange of the bar Ill to which the head is` attached. The head I 2, of course, extends the full length of the roller A and includes a flange I2b, a flange I2c set at right an- `gles to the flange I2b, a flange I2d set at right angles to the ange I2c and projecting in the same direction therefrom as does the flange I2b,

' and it also includes a short lip I2e projecting from the flange yI2d at 'right angles thereto in the' same direction as theange I2c projects therefrom. The head I2, accordingly, forms a channel I3 or way which is open at the forepart of thehead I2. n

Received 'within the channel I3 for reciprocating sliding movement therein, is a doctor blade holder which may be designated as an entirety by the letter C. This holder is of light weight and need not be of great strength inasmuch as it -is Jsupported by Mthe supporting head I2.` The holder C includes a bar I4 which is received `within the channel I3. It also includes a blade carrier I5 having a flat strip portion I5a which is received Within the channel I3 and -overlies the bar I4 and is secured to the said bar as by l means of screws' I6; The blade carrier I5 outwardly of the channel I3 has a portion I5b which vinclines diagonally downwardly from the strip portion lia, is equipped with a longitudinal rib I5c near its point of juncture with the strip portion I5a, is equipped with a second longitudinal rib I 5d somewhat outwardly from the rib |50, and is provided with a longitudinal groove I5e in its upper surface near itsv lower edge to produce a third portion. Where bearing rib If at its top outer the inclined portion Ib joins the strip portion Ia, an overlying substantially channel shaped bearing ilange 65g is produced by the carrier I5 and this bearing flange terminates in a. downwardly Idirected bearing edge lh. The carrier Iii in the illustrated embodiment is formed of light weight extruded metal, such as aluminum, and it carries a light weight thin doctor blade I'I made preferably of spring steel and it also carries a tensioning plate I8 also of thin spring steel. The upper edge of the doctor blade Il is received within a groove in theinclined portionlb of the carrier and it projects across the channel Ide and has bearing against the bearing rib E51. The tensioning plate I8 bears near its upper edge against the rib Ic and it bears at its lower edge against the doctor blade Il outwardly from the point where the doctor blade contacts-the bearing rib If. This tensioning plate I8 is also received between the rib I5@ and the bearing edge lh of the channel shaped portion Ig of the carrier. It Will thus be seen that `the light doctor blade I'I is properly supported by the carrier I5 and tensioned by the tensioning plate I8.

The holder C is supported for reciprocating sliding movement within the channel I3 of the head l2 by means o a plurality of rollers i9, 2li, and 2l respectively, these rollers in turn being journaled for rotation on pins 22, 23, and 28 respectively, carried by the bar Id. The rollers I9 are carried by the pins 22 which project outwardly from the forward edge of the bar I4 and these rollers work through recesses I5i in the strip.. portion Ilia -of the carrier I5 and bear against the under surface ofthe flange I2b of the head near the outer edge'thereof. The manner' in which the rollers I9 are mounted is best shown in Fig. 3.

As best shown in Fig. 5 the rollers 2@ are received within recesses 25 conjointly formed in the bar I4 and the strip portion ld'. of the cal'- rier I5 and the pins which .carry the rollers 2li extend into these recesses at the rear side of the bar I. The rollers bear downwardly.

against the ilange I2b of the head adjacent the rear portion thereof. The rollers 2|, as best shown in Fis. 4, are received within recesses 26 formed partially in the top-,surface of the bar Il and partially in the strip portion Ia of the carrier and, of course, the pins 24 project into these recesses 26 and the rollers 2| bearinwardlyagainst the flange I2c of the head adjacent the point where the flange I2 joins the ilange I2b, y

In Fig. 6 and in Fig'. 3 the detailed construction of one of the rollers I9 is illustrated, it being understood that the rollers 20 and 2l are of similar construction to the roller I9. The roller I9 is in reality a ball bearing and it includes an inner race I9a which is swaged on to the pin 22 carrying the roller and an outer -race Ib which forms the tire of the roller and balls I9c work between the two races I9a and I9b and are received within the channels thereof.

Secured to one end of the head I0 as by a VbraclretZI is a small fluid pressure reciprocating motor 28 which reciprocates a4 piston rod 29 working through a packing gland 30 carried Vby the motor 28. The fluid pressure reciproeating motor illustrated is o! similar construction to that shown in my United States application for patent Serial No. 159,305, filed August 16, 1937, entitled Reciprocating mechanism for paper making machines. The left end of the strip portion I5a of the carrier I5, in the illustrated embodiment, projects beyond the left end of the bar I4 and has secured thereto by means of screws 3l a yoke 32 which is connected by a pin 33 to the end of the piston rod 29.

It will be understood that the motor 28 will impart the reciprocating movement to the piston rod 29 land, oi course, this movement will be imparted from the rod 29 through the yoke 32 to the holder C. Accordingly the holder will move back and forth in the channel I3 of the head I2 with the doctor blade Il bearing against the roller A to be cleaned and being held under tension against the rollerby means of the tension plate I8. Of course, as the holder C reciprocates within the heady I2, the rollers I9,'20 and 2l which ride against the various portions or the head I2 will permit the light weight holder C to be properly guided and moved at an expenditure of but little force. The heavy head I2 supports the holder and gives the structure rigidity to assure cprrect and uniform pressure of the vdoctor blade over the full width of the roller A. The rollers I9, 20 and 2| are preferably staggered lengthwise of the holder C and, of course, the forward rollers I9 will prevent counterclockwise movement of the holder C in an upward direction, the rollers 2li will prevent counterclockwise movement of the holder in a downward direction, and the rollers 2I take the inward strain imposed upon the holders. Of course, these rollers form anti-friction supports for the holder. While only three such rollers are shown in ligs.- 1 and 2, it is, of course, obvious that the views are broken to indicate greater length and other groups of similarly positioned rollers are used depending upon the length of the mechanism in each installation.

It will be seen that the present device has decided advantages over other-types of reciprocating doctors wherein the complete structures for maintaining the doctor blades'against the rollers being cleaned are reciprocated.

It will, of course, be understood that variousl changes may be made in the form, details, arrangementand proportions of the various parts without departing from the scope of the present invention which generally stated consists in the matter shown and described and as set forth in the appended claim.

What is claimed is:

In a reciprocating doctor, an elongated, continuous, supporting head adapted to extend across a roller, said head having a longitudinal channel therein of rectangular shape in cross section and said channel being open at the front of the head, a light bar received within said channel, a doctor blade secured to said bar, said bar having a blade holding portion which projects through the opening in the forepart of said head, a doctor blade tensioner carried by said blade holding portion, anti-friction rollers carried by said bar andworking within said channel and supporting said bar for reciprocation therein, and means connected to said bar for reciprocating said bar together with said blade and tensioner y relative to said head.

ARTHUR E. BROUGHTON.' 

